In general, most electrical appliances for home use are manufactured to be operable under a specific source or township-supplied voltage.
However, when there is more than one source voltage supplied in a given locality, it becomes necessary to employ a voltage conversion device to operate electrical appliances whenever a source voltage, which is different from their design or operating voltage, is selected.
Therefore, in such a locality, generally provided with an electronic or electrical home product is a voltage conversion device capable of adapting the appliance to the changes in the source voltage.
Accordingly, various voltage switching devices have been disclosed in the prior art which purport to convert from one commercial voltage to another in order to facilitate the use of electronic and electrical products such as TV sets, microwave ovens, refrigerators, electrical tools and the like.
In Korean laid-open utility model publication No. 88-1321, there is provided voltage switching device comprising a first voltage (e.g., 100 V) and a second voltage(e.g., 220 V) fuses included in the internal circuitry of an appliance, wherein one of the fuses is selected by an external switch to convert a given source voltage to another corresponding to the driving voltage of the appliance.
This device is, however, handicapped by the inconvenient requirement of opening the casing of the appliance to gain access to the circuitry in order to check the state of the chosen fuse or remove and replace a broken fuse. Such tasks are not only cumbersome, but also difficult for an average user.
Furthermore, an additional fastening element is required to maintain the switch at a selected position and therefore results in a complicated structure and a greater volume for the switch.
Also, Korean laid-open utility model publication No. 87-19042 discloses a voltage switching device different from the type previously mentioned.
In this type of device, a first voltage and a second voltage fuses are housed in an external switch. Again, such a device is rather inconvenient for an ordinary consumer to handle since he needs to dissemble the switch box to perform the task of checking, placing or replacing a fuse.